Hepatobiliary scintigraphy of bile excretion after endoscopic ultrasound-guided hepaticogastrostomy for malignant biliary obstruction: a retrospective study in Japan

Background/Aims Hepatobiliary scintigraphy (HBS) is used to evaluate bile excretion. This study aimed to evaluate biliary excretion during endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) using HBS. Methods We retrospectively evaluated 78 consecutive patients with malignant extrahepatic biliary obstruction, who underwent HBS after EUS-HGS between April 2015 and July 2022. The peak time and decay rate were scored with 0, 1, or 2 points based on thresholds of 20 and 35 minutes, and 10% and 50%, respectively. A total score of 4 or 3 was considered indicative of good bile excretion, whereas scores of 2, 1, or 0 indicated poor bile excretion. Results The good and poor bile excretion groups included 40 and 38 cases, respectively. The group with good bile excretion had a significantly longer time to recurrent biliary obstruction compared to the poor bile excretion group (not reached vs. 124 days, p=0.026). Multivariate analysis identified the site of obstruction as a significant factor influencing good bile excretion (odds ratio, 3.39; 95% confidence interval, 1.01–11.4, p=0.049), with superior bile excretion observed in cases involving upper biliary obstruction compared to middle or lower biliary obstruction. Conclusions In patients with malignant biliary obstruction who underwent HGS, the site of obstruction is significantly associated with stent patency.